What about PFAS in mineral water and bottled water? Japan’s specification and the national survey
Since June 30, 2025, mineral water has had the same specification as tap water: “50 ng/L for the sum of PFOS and PFOA.” In the national survey (258 samples in total), one sample exceeded 50. We set out how the specification works and what overseas research found: values differ by source and treatment.
Short answer
Mineral water that is sterilized or sterile-filtered has had a compositional specification of “0.00005 mg/L (50 ng/L) or less as the sum of PFOS and PFOA” since June 30, 2025 (Cabinet Office Notice No. 105 of 2025). Products manufactured or imported by March 31, 2026 fall under transitional measures.
For water that is not sterilized or sterile-filtered (the natural mineral water type), 50 ng/L is applied for the time being through how the manufacturing standards are applied.
In the national survey (FY2021–FY2022, 258 samples in total), only one sample (56 ng/L) exceeded 50. But overseas research shows that values differ by source and treatment: spring water tends to be higher, and water treated by reverse osmosis (RO) lower.
Japan’s specification: two ways it is set
| Type | How it is set | Value | Timing |
|---|---|---|---|
| Mineral water that is sterilized or sterile-filtered | Compositional specification under the Food Sanitation Act (Cabinet Office Notice No. 105 of 2025) | PFOS + PFOA 50 ng/L or less | Issued and effective June 30, 2025. Products manufactured or imported by March 31, 2026 follow the previous rules |
| Water not sterilized or sterile-filtered | Application of the manufacturing standard “raw water must not contain man-made environmental pollutants” | 50 ng/L for the time being | Guidance on sanitary management of the spring source |
| Other soft drinks | The source water must be tap water or water that meets the mineral water specification | Indirectly the same | – |
| Water for food manufacturing | No specification (not a substitute for drinking water) | – | Voluntary management with 50 as a reference is desirable |
- The basis is the same formula as for tap water (2 L a day, 50 kg body weight, 10% of the TDI).
- The Consumer Affairs Agency explains that testing must be confirmed to measure PFOS and PFOA each down to 5 ng/L (one-tenth of the standard).
- For products with a carbon dioxide pressure of 98 kPa or more, voluntary management is considered desirable.
- Foods other than mineral water have no standard values for PFAS (MAFF).
The national survey (FY2021–FY2022)
| Fiscal year | Samples | Results (PFOS + PFOA) |
|---|---|---|
| FY2021 | 160 (126 domestic) | PFOS was below the quantification limit (2.5 ng/L) in all samples. PFOA was below the limit in 94%. Highest combined value 23 ng/L |
| FY2022 | 98 | One sample at 56 ng/L exceeded the provisional target value (the local government was informed, and later testing found it below the target value). Highest among the other 97 samples: 9.4 ng/L |
- Values are for linear isomers only.
Overseas research: values differ by source and treatment
| Study | Subject | Results |
|---|---|---|
| Chow et al. 2021 (U.S.) | 101 bottled water products, 32 PFAS | Detected in 39 products. Total 0.17–18.87 ng/L, median 0.98, 97% below 5 ng/L. Spring water tended to be higher; RO-treated “Purified” water lower |
| Quan et al. 2025 (China) | 52 bottled water products, 50 PFAS measured (21 detected) | Total 2.69–97.0 ng/L. Ultrashort-chain TFA and PFPrA were common. Spring water had the highest average (37.5); deep groundwater and RO-treated water were lower |
| Gao et al. 2024 (UK, China and others) | Tap water from the UK and China, and bottled water from 15 countries | PFOA and PFOS detected in more than 99% of bottled water (at low concentrations) |
- Overseas studies add up more substances than Japan’s specification covers (PFOS + PFOA). They can’t be compared directly with Japan’s 50.
- The U.S. has no standard value for PFAS in bottled water; regulation covers tap water only (as summarized by the Consumer Affairs Agency). In the EU, recognized natural mineral waters are outside the PFAS values of the Drinking Water Directive.
Compared with tap water
- For tap water too, most operations tested in the national survey were nd (below the lowest measurable level). As of November 2024, 98.2% of the population served was confirmed to receive water at 50 ng/L or less.
- It is not “bottled water, so zero PFAS,” nor “tap water, so it’s high.” For both, it comes down to where the water comes from and how it is treated.
- You can see your local tap water value in the guide to checking and on the prefecture pages, and ways to reduce it at home on the water filter page.
Sources
- Consumer Affairs Agency, Q&A on PFOS and PFOA in mineral water
- Consumer Affairs Agency and MHLW, Notice No. 402 (Cabinet Office Notice No. 105 of 2025, June 30, 2025)
- Ministry of the Environment, materials of the expert meeting on a comprehensive strategy for PFAS (August 2024, survey of mineral water)
- Chow et al. 2021, PFAS in 101 bottled water products (Water Res)（PMID 34118648）
- Quan et al. 2025, PFAS in 52 bottled water products in China (J Hazard Mater)（PMID 41138410）
- MAFF, Q&A on PFAS
Last checked 2026.10.04 (against the original government documents and papers, collected and cross-checked in Gemini Notebook). Utility values are as in the national table; Urayomi sorted and summarized them.